FLOOD WARNING & EVACUATION PLAN LIMEHOUSE MARINA, LONDON DECEMBER 2010

Transcription

1 FLOOD WARNING & EVACUATION PLAN LIMEHOUSE MARINA, LONDON DECEMBER 2010 No 2 Smithy Farm Chapel Lane Bruera Chester CH3 6EW Tel: Fax: info@weetwood.net

2 SIGNATURE SHEET Report Title : : Client : Report Status : Final Date of Issue : Prepared by : Carina Clarke BSc (Hons) Checked by : Emily Farquharson-Smith BSc (Hons) Approved by : Type name (qualifications) Every reasonable effort has been made to ensure that the information upon which this has been based is accurate and comprehensive at the date of production. It is the responsibility of the British Waterways Marinas Ltd to ensure that the plan is subsequently maintained up to date. Weetwood i 1778/Flood Evacuation Plan_ v1.0

3 CONTENTS Signature Sheet Contents List of Figures & Appendices Page i ii iii 1 INTRODUCTION SITE LOCATION FLOOD RISK: BE AWARE! EA FLOOD MAP FLOOD RISK RIVER THAMES River Thames Defences Lock System OTHER SOURCES OF FLOOD RISK Regents Canal and Limehouse Cut Surface Water Flooding Groundwater Flooding CLIMATE CHANGE PLANNING AND PROCEDURES: BE PREPARED! RECOMMENDED PLANNING PROCEDURES LONDON STRATEGIC FLOOD FRAMEWORK FLOOD WARNINGS- WATCH OUT! EA FLOOD WARNING CODES EA FLOODLINE WARNINGS DIRECT EA FLOODLINE LOCAL UPDATES FLOOD EVACUATION- ACT NOW! COMMUNICATION EVACUATION ROUTE DURING A FLOOD AFTER A FLOOD- ALL CLEAR! Weetwood ii 1778/Flood Evacuation Plan_ v1.0

4 LIST OF FIGURES Figure 1: Site Location...1 Figure 2: Environment Agency Flood Map...2 Figure 3: Lock System from Limehouse Basin...3 Figure 4: Regents Canal and Limehouse Cut...4 Figure 5: EA Floodline Warning Direct Areas...8 Figure 6: Suggested Evacuation Routes...9 LIST OF APPENDICES Appendix A: Flood Checklist Weetwood iii 1778/Flood Evacuation Plan_ v1.0

5 1 INTRODUCTION This has been produced to ensure that residential moorers at Limehouse Marina are satisfactorily prepared for a flood event and can escape from the site safely should such an event occur. The plan has been prepared in accordance with recommendations of Planning Policy Statement 25: Development and Flood Risk (PPS 25) Practice Guide, and in consultation with the Environment Agency (EA) and Tower Hamlets Emergency Planning Department, and considers: the potential risk of flooding at the site- be aware! how to prepare for a flood event- be prepared! how to receive flood messages and warnings- watch out! and most importantly how to respond safely to a flood event- act now! 1.1 SITE LOCATION Limehouse Marina is located on the north side of the River Thames in the London Borough of Tower Hamlets. It is located at Ordnance Survey national grid reference TQ , as shown in Figure 1. Commercial Road Regents Canal Limehouse Cut Branch Road Site Location Horseferry Road Image reproduced with permission of Ordnance Survey and Ordnance Survey of Northern Ireland Figure 1: Site Location Weetwood /Flood Evacuation Plan_v1.0

6 2 FLOOD RISK: BE AWARE! 2.1 EA FLOOD MAP According to the Environment Agency (EA) detailed flood map (Figure 2), the dockside areas surrounding the marina (to the north east, north, west and south west) are shown to be located within Flood Zone 1. Flood Zone 1 is defined as land assessed as having a less than 1 in 1000 annual probability of river flooding in any year (< 0.1%). The eastern portion of the marina is shown to be located within Flood Zone 2. Flood Zone 2 is defined as land assessed as having between a 1 in 100 and 1 in 1000 annual probability of river flooding in any year. The remainder of the marina is shown to be located within Flood Zone 3. Flood Zone 3 is defined as land assessed as having a 1 in 100 or greater annual probability of river flooding in any year. Given that there is only one basin already full with water, it is an anomaly as to why the basin is shown to be located within both Flood Zone 2 and Flood Zone 3. Site Location Crown copyright. All rights reserved. Environment Agency, , 2010 Flooding from rivers / sea without defences (1 in 100 yr) Flood Zone 3 Extent of extreme flood (1 in 1000 yr) Flood Zone 2 Flood defences Areas benefiting from flood defences Main rivers 1928 flood outline Figure 2: Environment Agency Flood Map 2.2 FLOOD RISK RIVER THAMES The River Thames is located approximately 150m to the south of Limehouse Marina, and is tidally influenced in this reach River Thames Defences The River Thames is protected from causing tidal flooding by a system comprising the Thames Barrier, seven other major flood barriers and tidal walls and embankments. Weetwood /Flood Evacuation Plan_v1.0

7 The EA has confirmed that the River Thames defences along this section of the river provide a standard of protection of 1 in Lock System The marina is connected to the River Thames via a lock system which prevents the marina being affected by any changes in the River Thames water levels 2. There are two radial sector lock gates, as shown in Figure 3. The top of the lock gate is at a height of 5.06m AOD (as measured during the topographic survey). River Thames Limehouse Basin a) First gate from River Thames b) Second gate into Limehouse Basin Figure 3: Lock System from Limehouse Basin The gates on the entrance lock to the marina are regularly inspected and maintained structures. The probability of failure of both these gates is considered extremely low. 2.3 OTHER SOURCES OF FLOOD RISK Although the River Thames is considered to be the primary source of flood risk to Limehouse Marina, it is important to have an awareness of other potential sources of flood risk Regents Canal and Limehouse Cut Regents Canal and the Limehouse Cut connect into the Limehouse Basin. All the locks, docks and basins in the vicinity of the site are owned and operated by British Waterways (BW) and as such would be subject to regular maintenance inspections. 1 Letter from EA to Weetwood, 14 September 2010, ref NE24968/AS 2 Telephone conversation with British Waterways, 20 September 2010 Weetwood /Flood Evacuation Plan_v1.0

8 a) Regents Canal b) Limehouse Cut Figure 4: Regents Canal and Limehouse Cut Surface Water Flooding Surface water flooding describes flooding from sewers, drains, and ditches that occurs during heavy rainfall in urban areas. It includes 3 : Pluvial flooding - flooding as a result of high intensity rainfall when water is ponding or flowing over the ground surface (surface runoff) before it enters the underground drainage network or watercourse, or cannot enter it because the network is full to capacity. Sewer flooding - flooding which occurs when the capacity of underground sewer systems is exceeded, resulting in flooding inside and outside of buildings. Normal discharge of sewers and drains through outfalls may be impeded by high water levels in receiving waters. There are no known records of surface water flooding at or in the immediate vicinity of the site Groundwater Flooding Groundwater flooding generally occurs during intense, long-duration rainfall events, when infiltration of rainwater into the ground raises the level of the water table until it exceeds ground levels. The propensity for groundwater flooding at the site is considered to be low and is therefore not considered to pose a risk to the site. 2.4 CLIMATE CHANGE The PPS25Practice Guide states that a should take account of the likely impacts of climate change by being aware of the likely implications. 3 Defra (2009) Surface Water Management Plan Technical Guidance; Living Draft Version 1 Weetwood /Flood Evacuation Plan_v1.0

9 The UK Climate Projections 09 (UKCP09) provides the latest information on how continued emissions of greenhouse gases may change the UK s climate over the 21st century. Key findings of UKCP09 are summarised below. UKCP09 Key Findings include: all areas of the UK get warmer, and the warming is greater in summer than in winter there is little change in the amount of annual precipitation, but it is likely that more of it will fall in the winter, with drier summers there will be an increase in frequency of intense rainfall events sea levels rise, and are greater in the south of the UK than the north UKCP09 identifies the likely impacts of climate change on flood risk as: increased river and surface water flooding, due to the increased incidence and severity of extreme rainfall events increased pressure on sewer systems with associated impacts on diffuse pollution and sewer flooding incidents Climate change has been taken into account in the design of the moorings to ensure that they remain safe over their lifetime. Weetwood /Flood Evacuation Plan_v1.0

10 3 PLANNING AND PROCEDURES: BE PREPARED! 3.1 RECOMMENDED PLANNING PROCEDURES The responsibility to prepare for a flood event and implement the flood warning and evacuation procedures lies with the residential moorers. The following procedures are recommended: Planning Procedures Regularly review/update the Plan and Flood Checklist (Appendix A) (ensure that telephone numbers are still valid; liaise with the EA and Tower Hamlets to determine whether there are any changes in the way they operate) Make up a flood kit including key documents, torch, mobile phone, waterproof clothing, first aid kit Be aware of and monitor the current situation (i.e. in times of adverse weather use local information and observations, check local media, weather reports, EA website) Help and assist vulnerable people on site At no time should you put your own life at risk 3.2 LONDON STRATEGIC FLOOD FRAMEWORK The London Strategic Flood Framework 4 has been prepared by London Resilience in order to ensure that is to ensure a coordinated response, which will protect life and well-being with mitigation of property and environmental damage. It is recommended that the Flood Plan Coordinator reviews the plan and retains a copy along with this. It is recommended that the London Resilience website is regularly checked for any updates to the plan. 4 London Resilience The London Strategic Flood Framework (January 2010) Weetwood /Flood Evacuation Plan_v1.0

11 4 FLOOD WARNINGS- WATCH OUT! 4.1 EA FLOOD WARNING CODES The EA has recently updated their flood warnings (November 2010). EA flood warnings are now issued using a set of three recognisable codes. Each of the three codes indicates the level of danger associated with the warning, as detailed below. Code Meaning EA General Advice Flood Alert! Flooding is possible be prepared (used 2 hours to 2 days in advance of flooding) Flood Warning! Flooding is expected - immediate action required (used half an hour to one day in advance of flooding.) Severe Flood Warning! Severe flooding Danger to life (used when flooding poses a significant threat to life) Be prepared to act on your flood plan Prepare a flood kit of essential items Monitor local water levels and the flood forecast on the EA website Move family, pets and valuables to a safe place Turn off gas, electricity and water supplies if safe to do so Put flood protection equipment in place Stay in a safe place with a means of escape Be ready should you need to evacuate from your home Co-operate with the emergency services Call 999 if you are in immediate danger Weetwood /Flood Evacuation Plan_v1.0

12 4.2 EA FLOODLINE WARNINGS DIRECT The EA offers a free flood warning service called Floodline Warnings Direct (FWD) in many areas at risk of flooding from rivers and the sea. As shown in Figure 5 Limehouse Marina is covered by the FWD service. Site Location Figure 5: EA Floodline Warning Direct Areas It is recommended that residential moorers (and the BWML office) register with the EA to receive flood warning information. More information on this service can be found by visiting the EA s website ( 4.3 EA FLOODLINE In times of adverse weather residential moorers may telephone Floodline on for recorded local flood warnings and enter the quickdial code LOCAL UPDATES Crown copyright. All rights reserved. Environment Agency, , 2010 EA Floodline Warning Direct area Local updates on flooding are also available from the following services: Radio: Television: Online: LBC News 1152 AM BBC London, ITV London EA (environment-agency.gov.uk) Met Office (metoffice.gov.uk) Weetwood /Flood Evacuation Plan_v1.0

13 5 FLOOD EVACUATION- ACT NOW! If a Flood Warning or Severe Flood Warning code is received from the EA (via Floodline/ Local Updates as identified in Section 4), the Flood Warning and Evacuation Plan may need to be implemented. 5.1 COMMUNICATION It is essential that communication is coordinated and consistent. 5.2 EVACUATION ROUTE Pedestrian access and egress for Limehouse Marina is provided off a number of walkways located around the marina, which lead to Branch Road. Vehicular access and egress is provided along Horseferry Road, which also leads to Branch Road. Branch Road subsequently leads in a northerly direction towards Commercial Road. The suggested evacuation route (Figure 6) is based on the safest route to take should flooding occur. However any advice provided by the Emergency Services, EA or Tower Hamlets regarding whether and where to evacuate should be adhered to. Commercial Road Site Location Branch Road Horseferry Road Site Location Image reproduced with permission of Ordnance Survey & Ordnance Survey of Northern Ireland Suggested Evacuation Route Crown copyright. All rights reserved. Environment Agency, , 2010 Flood Zone 3 Flood Zone 2 Figure 6: Suggested Evacuation Routes Weetwood /Flood Evacuation Plan_v1.0

14 Remember Floods Can Kill! don't walk through flowing water currents can be deceptive, and shallow, fast moving water can knock you off your feet if you have to walk in standing water, use a pole or stick to ensure that you do not step into deep water, open manholes or ditches don't drive through a flooded area only half a metre of floodwater can carry a car away stay away from power lines electrical current can travel through water look before you step after a flood, the ground and floors can be covered with debris, which may include broken bottles, sharp objects and nails. Floors and stairs covered with mud and debris can be slippery. avoid contact with floodwater Weetwood /Flood Evacuation Plan_v1.0

15 6 DURING A FLOOD The EA: issue flood warnings receive and record details of flooding incidents monitor the situation and advise other organisations deal with emergency repairs and blockages on main rivers and own structures respond to pollution incidents advise on waste disposal issues Local Authority: work with the police, fire and rescue services and the EA to co-ordinate the response during severe flooding provide emergency assistanceprovide sandbags provide short term emergency shelter clear blocked watercourses (Land Drainage Act powers) deal with environmental health issuespollution clear blocked road channels and gullies establish additional community information and enquiry services Thames Water: The Police: take an overall co-ordination role during an incident The Fire and Rescue Service: rescue respond to all emergency incidents as required assist the populace where a need is identified and the use of Fire Service personnel and equipment is relevant clear blockages in public sewers may take action to protect property from flooding by water from the public water mains or discharges from the public sewerage systems Electricity, Gas and Telecommunication companies: attend to emergencies relating to their service at properties where life is at risk as a result of flooding attend to flooding emergencies at their own serviced installations These agencies work together within pre-set structures to ensure a coordinated multi-agency response. Weetwood /Flood Evacuation Plan_v1.0

16 7 AFTER A FLOOD- ALL CLEAR! When EA Flood Warnings are no longer in force, no further flooding is expected. However, caution should still be taken until floodwaters have receded. Following a flood event: take care as there may be hidden dangers in the floodwater like sharp objects, raised manhole covers and pollution (floodwater can contain sewage, chemicals and animal waste). Floodwater may have also caused structural damage throw away food which may have been in contact with floodwater - it could be contaminated. Contact Tower Hamlets Environmental Health department for advice have power supplies checked before you use them to make sure they have dried out. Wash taps and run them for a few minutes before use keep a record of the flood damage (especially photographs or video footage) Weetwood /Flood Evacuation Plan_v1.0

17 APPENDICES APPENDIX A: Flood Checklist Date: Site: Limehouse Marina General contact list Company name Contact name Telephone Floodline Floodline Mobile EA EA Tower Hamlets Electricity provider Gas provider Water company Telephone provider Local public transport Insurance company Insurance agent Services Service cut-off Description of location Electricity Gas Water Weetwood 1778/Flood Evacuation Plan_v1.0

18 Items to consider Item Way to Protect Computers / Files Records / Important Documents Databases Other Weetwood 1778/Flood Evacuation Plan_v1.0